<p>
  <span :title="message">
    Hover your mouse over me for a few seconds to see my dynamically bound title!
  </span>
</p>

<!--
除了普通字符串之外，
class 绑定还特别支持了对象和数组
-->
<p :class="{ red: isRed }" @click="toggleRed">
  This should be red... but click me to toggle it.
</p>

<!-- 样式绑定也支持对象和数组 -->
<p :style="{ color }" @click="toggleColor">
  This should be green, and should toggle between green and blue on click.
</p>
